Recently, as network becomes widespread, a personal computer (PC) can immediately transmit data to the outside. Recently, a composite machine combining a copy function, a facsimile function and a print function becomes diversified to be added with a function for sending transmitted print data, read image data or data accumulated in a hard disk to an external apparatus, and data transmission to the outside is easily enabled in the composite machine as well. As a function for transmitting to an external apparatus in the composite machine, functions such as “Scan to Email”, “Scan to FAX” and “Scan to FTP (File Transfer Protocol)” are widely utilized. These functions can also be realized if a scanner is connected to a PC directly or via network.
As described above, since data can be easily transmitted from a PC or composite machine, in addition to management of data reception, an apparatus on the transmission side stores transmission histories such as transmission destinations, transmission dates and time and others associated with data transmission and manages data transmission.
However, in this day and age when a PC becomes diversified, since a plurality of PCs is often assigned to one (1) individual, it is difficult to manage transmission histories for data such as image data transmitted from an individual PC. As a reason, if data are transmitted from a PC, the transmission history is stored in the PC used by an individual and the transmission history can be easily deleted by the user.
Therefore, in order to centrally manage transmission and reception of data, a mail server, FTP server or the like is often used for transmitting and receiving data. This server is connected to a PC via network such as LAN, and all the data transmitted from the PC is sent to the server via the network and is transmitted to the outside via the server. In addition to reception histories accumulated in accordance with data reception, the server accumulates transmission histories as log information in accordance with data transmission.
Even if overall central management is performed by a server in this way, in terms of e-mail transmission, for example, it is problematic for security that important data are transmitted to the outside of a company, which should have been transmitted within the company, and a social problem has been presented by bad manners such as transmitting e-mails to superiors of outside companies as if transmitting e-mails to friends. Not exclusively to e-mails, transmission of data of one's own or others to the outside may happen as the case of blindly accessing to data even though an operation procedure is not known or as the case of an operation error generated carelessly by a user, as well as may be performed maliciously.
A transmission apparatus is proposed for limiting transmission depending on a size of data to be transmitted when the data are transmitted through a communication line (e.g., see Japanese Laid-Open Patent Publication No. 2003-333295). Along with transmission destination information indicating a transmission destination of data, the transmission apparatus described in Japanese Laid-Open Patent Publication No. 2003-333295 has a data table storing transmission-permitted size information indicating a data size permitted to be transmitted to the transmission destination and is configured to refer to the data table to determine whether transmission can be performed or not, when data are transmitted to a specified transmission destination, depending on the transmission-permitted size information of the transmission destination.
An image communication apparatus is proposed for reducing a load due to facsimile transfer of FAX data with a large size, or for preventing facsimile transfer of a wrong or unnecessary e-mail, or for appropriately notifying a sender or a transfer destination of a transfer result, when content of a received e-mail is transferred by facsimile (FAX) (e.g., see Japanese Laid-Open Patent Publication No. 2004-289440). In the image communication apparatus described in Japanese Laid-Open Patent Publication No. 2004-289440, a mail analysis portion analyzes a received mail received by a mail reception control portion to obtain a transmission destination address or transfer destination address and it is determined whether transfer is needed or not, by referring to a transfer list and an address book stored in auxiliary memory portion. If it is determined that the received mail is to be transferred, a communication control portion checks transfer conditions based on system data such as a transfer upper-limit size and a transfer time to conduct transfer cancellation, immediate transfer, divided transfer or timed transfer as well as transmits a transfer result to a source of the transfer instruction (in the case of an e-mail sender, a report is returned by an e-mail from a mail transmission/reception control portion, or in the case of a transfer list, a transfer result is transmitted by FAX from the communication control portion).
As described above, for e-mail transmission of a mail server, file transmission of an FTP server, facsimile transmission of a FAX machine and the like, even if overall central management is performed by a server, security problems are generated by the case such that data prohibited to be transmitted are transmitted by wrong transmission or maliciously. In the apparatuses described in Japanese Laid-Open Patent Publication No. 2003-333295 and Japanese Laid-Open Patent Publication No. 2004-289440, transmission to the outside can only be limited in data capacity and similar problems may be generated.
Since log information accumulated in the server is an enormous amount and the log cannot be accessed for retrieval and, of course, cannot be browsed unless authorized as an administrator of the server, a general user is almost impossible to retrieve and browse past transmission histories. By transmitting data from a PC to the outside via a server, although a transmission record is left as log information in the PC in addition to log information accumulated in the server, since this log information is, of course, under the supervision of an individual in a current usage environment, retrieval and browse of transmission histories in the PCs of others are almost impossible because a multiplicity of individual PCs exists as well as because of password protection and the like. Therefore, in the current usage environment, comprehensive log management is impossible for data transmission to the outside, and this is the same even if applying the apparatuses described in Japanese Laid-Open Patent Publication No. 2003-333295 and Japanese Laid-Open Patent Publication No. 2004-289440.